This invention relates to security systems that automatically detect and indicate intrusions into a protected area. It relates particularly to a signal processor for such a system that is capable of distinguishing between human and vehicular intrusions.
Security systems of the type to which this invention pertains are commonly used to protect important areas such as airports and other strategic locations from intrusions by unorthorized persons and vehicles. Such systems employ sensor (transducing) elements that encompass the area to be protected. Various types of sensor elements and detecting schemes are used. All, however, develop a signal in response to an intrusion event. The signal is used for alarm and surveillance purposes.
Although systems of this type are generally effective they are subject to some limitations and deficiencies that state-of-the-art technology has yet to overcome. Specifically, it would be desirable in many instances to be able to distinguish between a human intrusion and a vehicular intrusion. For instance, if one type of intrusion was permitted and the other was not. Security systems currently in use normally cannot reliably distinguish between various classes of intruders.
Another problem encountered with state-of-the-art security systems is the occurrances of false alarms due to wind and other non-relevant transducer actuating events. Also inefficient transducer operation is often encountered under adverse environmental conditions such as frozen ground and the like.
Accordingly, there currently exists the need for signal processing equipment that can provide reliable, unambiguous information from conventional security system transducer outputs and that overcomes the above noted deficiencies and limitations of known security systems.
The present invention is directed toward satisfying that need.